##
## This file is part of the sigrok project.
##
## Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 3 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, see <http://www.gnu.org/licenses/>.
##
# EDID protocol decoder
# TODO:
# - EDID < 1.3
# - add short annotations
# - Signal level standard field in basic display parameters block
# - Additional color point descriptors
# - Additional standard timing descriptors
# - Extensions
import sigrokdecode as srd
import os
EDID_HEADER = [0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00]
OFF_VENDOR = 8
OFF_VERSION = 18
OFF_BASIC = 20
OFF_CHROM = 25
OFF_EST_TIMING = 35
OFF_STD_TIMING = 38
OFF_DET_TIMING = 54
OFF_NUM_EXT = 126
OFF_CHECKSUM = 127
# Pre-EDID established timing modes
est_modes = [
'720x400@70Hz',
'720x400@88Hz',
'640x480@60Hz',
'640x480@67Hz',
'640x480@72Hz',
'640x480@75Hz',
'800x600@56Hz',
'800x600@60Hz',
'800x600@72Hz',
'800x600@75Hz',
'832x624@75Hz',
'1024x768@87Hz(i)',
'1024x768@60Hz',
'1024x768@70Hz',
'1024x768@75Hz',
'1280x1024@75Hz',
'1152x870@75Hz',
]
# X:Y display aspect ratios, as used in standard timing modes
xy_ratio = [
(16, 10),
(4, 3),
(5, 4),
(16, 9),
]
# Annotation types
ANN_FIELDS = 0
ANN_SECTIONS = 1
class Decoder(srd.Decoder):
api_version = 1
id = 'edid'
name = 'EDID'
longname = 'Extended display identification data'
desc = 'A data structure describing the capabilities of a display device.'
license = 'gplv3+'
inputs = ['ddc2']
outputs = ['edid']
options = {}
annotations = [
['EDID fields', 'EDID structure fields'],
['EDID sections', 'EDID structure sections'],
]
def __init__(self, **kwargs):
self.state = None
# Received data items, used as an index into samplenum/data
self.cnt = 0
# Start/end sample numbers per data item
self.sn = []
# Received data
self.cache = []
def start(self, metadata):
self.out_ann = self.add(srd.OUTPUT_ANN, 'edid')
def decode(self, ss, es, data):
if type(data) != int:
raise Exception('malformed ddc2 input: expected 1 byte')
self.cnt += 1
self.sn.append([ss, es])
self.cache.append(data)
# debug
# self.put(ss, es, self.out_ann, [0, ['%d: [%.2x]' % (self.cnt, data)]])
if self.state is None:
# Wait for the EDID header
if self.cnt >= OFF_VENDOR:
if self.cache[-8:] == EDID_HEADER:
# Throw away any garbage before the header
self.sn = self.sn[-8:]
self.cache = self.cache[-8:]
self.cnt = 8
self.state = 'edid'
self.put(ss, es, self.out_ann, [0, ['EDID header']])
elif self.state == 'edid':
if self.cnt == OFF_VERSION:
self.decode_vid(-10)
self.decode_pid(-8)
self.decode_serial(-6)
self.decode_mfrdate(-2)
elif self.cnt == OFF_BASIC:
version = 'EDID version: %d.%d' % (self.cache[-2], self.cache[-1])
self.put(ss, es, self.out_ann, [0, [version]])
elif self.cnt == OFF_CHROM:
self.decode_basicdisplay(-5)
elif self.cnt == OFF_EST_TIMING:
self.decode_chromaticity(-10)
elif self.cnt == OFF_STD_TIMING:
self.decode_est_timing(-3)
elif self.cnt == OFF_DET_TIMING:
self.decode_std_timing(-16)
elif self.cnt == OFF_NUM_EXT:
self.decode_descriptors(-72)
elif self.cnt == OFF_CHECKSUM:
self.put(ss, es, self.out_ann,
[0, ['Extensions present: %d' % self.cache[self.cnt-1]]])
elif self.cnt == OFF_CHECKSUM+1:
checksum = 0
for i in range(128):
checksum += self.cache[i]
if checksum % 256 == 0:
csstr = 'OK'
else:
csstr = 'WRONG!'
self.put(ss, es, self.out_ann, [0, ['Checksum: %d (%s)' % (
self.cache[self.cnt-1], csstr)]])
self.state = 'extensions'
elif self.state == 'extensions':
pass
def ann_field(self, start, end, annotation):
self.put(self.sn[start][0], self.sn[end][1],
self.out_ann, [ANN_FIELDS, [annotation]])
def lookup_pnpid(self, pnpid):
pnpid_file = os.path.join(os.path.dirname(__file__), 'pnpids.txt')
if os.path.exists(pnpid_file):
for line in open(pnpid_file).readlines():
if line.find(pnpid + ';') == 0:
return line[4:].strip()
return ''
def decode_vid(self, offset):
pnpid = chr(64 + ((self.cache[offset] & 0x7c) >> 2))
pnpid += chr(64 + (((self.cache[offset] & 0x03) << 3)
| ((self.cache[offset+1] & 0xe0) >> 5)))
pnpid += chr(64 + (self.cache[offset+1] & 0x1f))
vendor = self.lookup_pnpid(pnpid)
if vendor:
pnpid += ' (%s)' % vendor
self.ann_field(offset, offset+1, pnpid)
def decode_pid(self, offset):
pidstr = 'Product 0x%.2x%.2x' % (self.cache[offset+1], self.cache[offset])
self.ann_field(offset, offset+1, pidstr)
def decode_serial(self, offset):
serialnum = (self.cache[offset+3] << 24) \
+ (self.cache[offset+2] << 16) \
+ (self.cache[offset+1] << 8) \
+ self.cache[offset]
serialstr = ''
is_alnum = True
for i in range(4):
if not chr(self.cache[offset+3-i]).isalnum():
is_alnum = False
break
serialstr += chr(self.cache[offset+3-i])
serial = serialstr if is_alnum else str(serialnum)
self.ann_field(offset, offset+3, 'Serial ' + serial)
def decode_mfrdate(self, offset):
datestr = ''
if self.cache[offset]:
datestr += 'week %d, ' % self.cache[offset]
datestr += str(1990 + self.cache[offset+1])
if datestr:
self.ann_field(offset, offset+1, 'Manufactured ' + datestr)
def decode_basicdisplay(self, offset):
# Video input definition
vid = self.cache[offset]
if vid & 0x80:
# Digital
self.ann_field(offset, offset, 'Video input: VESA DFP 1.')
else:
# Analog
sls = (vid & 60) >> 5
self.ann_field(offset, offset, 'Signal level standard: %.2x' % sls)
if vid & 0x10:
self.ann_field(offset, offset, 'Blank-to-black setup expected')
syncs = ''
if vid & 0x08:
syncs += 'separate syncs, '
if vid & 0x04:
syncs += 'composite syncs, '
if vid & 0x02:
syncs += 'sync on green, '
if vid & 0x01:
syncs += 'Vsync serration required, '
if syncs:
self.ann_field(offset, offset, 'Supported syncs: %s' % syncs[:-2])
# Max horizontal/vertical image size
if self.cache[offset+1] != 0 and self.cache[offset+2] != 0:
# Projectors have this set to 0
sizestr = '%dx%dcm' % (self.cache[offset+1], self.cache[offset+2])
self.ann_field(offset+1, offset+2, 'Physical size: ' + sizestr)
# Display transfer characteristic (gamma)
if self.cache[offset+3] != 0xff:
gamma = (self.cache[offset+3] + 100) / 100
self.ann_field(offset+3, offset+3, 'Gamma: %1.2f' % gamma)
# Feature support
fs = self.cache[offset+4]
dpms = ''
if fs & 0x80:
dpms += 'standby, '
if fs & 0x40:
dpms += 'suspend, '
if fs & 0x20:
dpms += 'active off, '
if dpms:
self.ann_field(offset+4, offset+4, 'DPMS support: %s' % dpms[:-2])
dt = (fs & 0x18) >> 3
dtstr = ''
if dt == 0:
dtstr = 'Monochrome'
elif dt == 1:
dtstr = 'RGB color'
elif dt == 2:
dtstr = 'non-RGB multicolor'
if dtstr:
self.ann_field(offset+4, offset+4, 'Display type: %s' % dtstr)
if fs & 0x04:
self.ann_field(offset+4, offset+4, 'Color space: standard sRGB')
# Save this for when we decode the first detailed timing descriptor
self.have_preferred_timing = (fs & 0x02) == 0x02
if fs & 0x01:
gft = ''
else:
gft = 'not '
self.ann_field(offset+4, offset+4,
'Generalized timing formula: %ssupported' % gft)
def convert_color(self, value):
# Convert from 10-bit packet format to float
outval = 0.0
for i in range(10):
if value & 0x01:
outval += 2 ** -(10-i)
value >>= 1
return outval
def decode_chromaticity(self, offset):
redx = (self.cache[offset+2] << 2) + ((self.cache[offset] & 0xc0) >> 6)
redy = (self.cache[offset+3] << 2) + ((self.cache[offset] & 0x30) >> 4)
self.ann_field(offset, offset+9, 'Chromacity red: X %1.3f, Y %1.3f' % (
self.convert_color(redx), self.convert_color(redy)))
greenx = (self.cache[offset+4] << 2) + ((self.cache[offset] & 0x0c) >> 6)
greeny = (self.cache[offset+5] << 2) + ((self.cache[offset] & 0x03) >> 4)
self.ann_field(offset, offset+9, 'Chromacity green: X %1.3f, Y %1.3f' % (
self.convert_color(greenx), self.convert_color(greeny)))
bluex = (self.cache[offset+6] << 2) + ((self.cache[offset+1] & 0xc0) >> 6)
bluey = (self.cache[offset+7] << 2) + ((self.cache[offset+1] & 0x30) >> 4)
self.ann_field(offset, offset+9, 'Chromacity blue: X %1.3f, Y %1.3f' % (
self.convert_color(bluex), self.convert_color(bluey)))
whitex = (self.cache[offset+8] << 2) + ((self.cache[offset+1] & 0x0c) >> 6)
whitey = (self.cache[offset+9] << 2) + ((self.cache[offset+1] & 0x03) >> 4)
self.ann_field(offset, offset+9, 'Chromacity white: X %1.3f, Y %1.3f' % (
self.convert_color(whitex), self.convert_color(whitey)))
def decode_est_timing(self, offset):
# Pre-EDID modes
bitmap = (self.cache[offset] << 9) \
+ (self.cache[offset+1] << 1) \
+ ((self.cache[offset+2] & 0x80) >> 7)
modestr = ''
for i in range(17):
if bitmap & (1 << (16-i)):
modestr += est_modes[i] + ', '
if modestr:
self.ann_field(offset, offset+2,
'Supported establised modes: %s' % modestr[:-2])
def decode_std_timing(self, offset):
modestr = ''
for i in range(0, 16, 2):
if self.cache[offset+i] == 0x01 and self.cache[offset+i+1] == 0x01:
# Unused field
continue
x = (self.cache[offset+i] + 31) * 8
ratio = (self.cache[offset+i+1] & 0xc0) >> 6
ratio_x, ratio_y = xy_ratio[ratio]
y = x / ratio_x * ratio_y
refresh = (self.cache[offset+i+1] & 0x3f) + 60
modestr += '%dx%d@%dHz, ' % (x, y, refresh)
if modestr:
self.ann_field(offset, offset+2,
'Supported standard modes: %s' % modestr[:-2])
def decode_detailed_timing(self, offset):
if offset == -72 and self.have_preferred_timing:
# Only on first detailed timing descriptor
section = 'Preferred'
else:
section = 'Detailed'
section += ' timing descriptor'
self.put(self.sn[offset][0], self.sn[offset+18][1],
self.out_ann, [ANN_SECTIONS, [section]])
pixclock = float((self.cache[offset+1] << 8) + self.cache[offset]) / 100
self.ann_field(offset, offset+1, 'Pixel clock: %.2f MHz' % pixclock)
horiz_active = ((self.cache[offset+4] & 0xf0) << 4) + self.cache[offset+2]
self.ann_field(offset+2, offset+4, 'Horizontal active: %d' % horiz_active)
horiz_blank = ((self.cache[offset+4] & 0x0f) << 8) + self.cache[offset+3]
self.ann_field(offset+3, offset+4, 'Horizontal blanking: %d' % horiz_blank)
vert_active = ((self.cache[offset+7] & 0xf0) << 4) + self.cache[offset+5]
self.ann_field(offset+5, offset+7, 'Vertical active: %d' % vert_active)
vert_blank = ((self.cache[offset+7] & 0x0f) << 8) + self.cache[offset+6]
self.ann_field(offset+6, offset+7, 'Vertical blanking: %d' % vert_blank)
horiz_sync_off = ((self.cache[offset+11] & 0xc0) << 2) + self.cache[offset+8]
self.ann_field(offset+8, offset+11, 'Horizontal sync offset: %d' % horiz_sync_off)
horiz_sync_pw = ((self.cache[offset+11] & 0x30) << 4) + self.cache[offset+9]
self.ann_field(offset+9, offset+11, 'Horizontal sync pulse width: %d' % horiz_sync_pw)
vert_sync_off = ((self.cache[offset+11] & 0x0c) << 2) \
+ ((self.cache[offset+10] & 0xf0) >> 4)
self.ann_field(offset+10, offset+11, 'Vertical sync offset: %d' % vert_sync_off)
vert_sync_pw = ((self.cache[offset+11] & 0x03) << 4) \
+ (self.cache[offset+10] & 0x0f)
self.ann_field(offset+10, offset+11, 'Vertical sync pulse width: %d' % vert_sync_pw)
horiz_size = ((self.cache[offset+14] & 0xf0) << 4) + self.cache[offset+12]
vert_size = ((self.cache[offset+14] & 0x0f) << 8) + self.cache[offset+13]
self.ann_field(offset+12, offset+14, 'Physical size: %dx%dmm' % (horiz_size, vert_size))
horiz_border = self.cache[offset+15]
if horiz_border:
self.ann_field(offset+15, offset+15, 'Horizontal border: %d pixels' % horiz_border)
vert_border = self.cache[offset+16]
if vert_border:
self.ann_field(offset+16, offset+16, 'Vertical border: %d lines' % vert_border)
features = 'Flags: '
if self.cache[offset+17] & 0x80:
features += 'interlaced, '
stereo = (self.cache[offset+17] & 0x60) >> 5
if stereo:
if self.cache[offset+17] & 0x01:
features += '2-way interleaved stereo ('
features += ['right image on even lines',
'left image on even lines',
'side-by-side'][stereo-1]
features += '), '
else:
features += 'field sequential stereo ('
features += ['right image on sync=1', 'left image on sync=1',
'4-way interleaved'][stereo-1]
features += '), '
sync = (self.cache[offset+17] & 0x18) >> 3
sync2 = (self.cache[offset+17] & 0x06) >> 1
posneg = ['negative', 'positive']
features += 'sync type '
if sync == 0x00:
features += 'analog composite (serrate on RGB)'
elif sync == 0x01:
features += 'bipolar analog composite (serrate on RGB)'
elif sync == 0x02:
features += 'digital composite (serrate on composite polarity ' \
+ (posneg[sync2 & 0x01]) + ')'
elif sync == 0x03:
features += 'digital separate ('
features += 'Vsync polarity ' + (posneg[(sync2 & 0x02) >> 1])
features += ', Hsync polarity ' + (posneg[sync2 & 0x01])
features += ')'
features += ', '
self.ann_field(offset+17, offset+17, features[:-2])
def decode_descriptor(self, offset):
tag = self.cache[offset+3]
if tag == 0xff:
# Monitor serial number
text = bytes(self.cache[offset+5:][:13]).decode(encoding='cp437', errors='replace')
self.ann_field(offset, offset+17, 'Serial number: %s' % text.strip())
elif tag == 0xfe:
# Text
text = bytes(self.cache[offset+5:][:13]).decode(encoding='cp437', errors='replace')
self.ann_field(offset, offset+17, 'Info: %s' % text.strip())
elif tag == 0xfc:
# Monitor name
text = bytes(self.cache[offset+5:][:13]).decode(encoding='cp437', errors='replace')
self.ann_field(offset, offset+17, 'Model name: %s' % text.strip())
elif tag == 0xfd:
# Monitor range limits
self.put(self.sn[offset][0], self.sn[offset+17][1], self.out_ann,
[ANN_SECTIONS, ['Monitor range limits']])
self.ann_field(offset+5, offset+5, 'Minimum vertical rate: %dHz' %
self.cache[offset+5])
self.ann_field(offset+6, offset+6, 'Maximum vertical rate: %dHz' %
self.cache[offset+6])
self.ann_field(offset+7, offset+7, 'Minimum horizontal rate: %dkHz' %
self.cache[offset+7])
self.ann_field(offset+8, offset+8, 'Maximum horizontal rate: %dkHz' %
self.cache[offset+8])
self.ann_field(offset+9, offset+9, 'Maximum pixel clock: %dMHz' %
(self.cache[offset+9] * 10))
if self.cache[offset+10] == 0x02:
# Secondary GTF curve supported
self.ann_field(offset+10, offset+17, 'Secondary timing formula supported')
elif tag == 0xfb:
# Additional color point data
self.put(self.sn[offset][0], self.sn[offset+17][1], self.out_ann,
[ANN_SECTIONS, ['Additional color point data']])
elif tag == 0xfa:
# Additional standard timing definitions
self.put(self.sn[offset][0], self.sn[offset+17][1], self.out_ann,
[ANN_SECTIONS, ['Additional standard timing definitions']])
else:
self.put(self.sn[offset][0], self.sn[offset+17][1], self.out_ann,
[ANN_SECTIONS, ['Unknown descriptor']])
def decode_descriptors(self, offset):
# 4 consecutive 18-byte descriptor blocks
for i in range(offset, 0, 18):
if self.cache[i] != 0 and self.cache[i+1] != 0:
self.decode_detailed_timing(i)
else:
if self.cache[i+2] == 0 or self.cache[i+4] == 0:
self.decode_descriptor(i)